Russia's Gazprom assured European customers it would continue to supply their gas, after its threat to halts supplies to transit nation Ukraine next month over non-payment. Any shortfall would be the fault of Ukraine, chief executive Alexei Miller told Russian television. Moscow blamed theft by Ukraine for a disruption to exports in a previous dispute. Russia has warned that it will not supply Ukraine with gas in June unless Kiev pays in advance $1.66 billion by June 2, raising fears that gas piped to Europe through Ukraine could be affected. "Gazprom will simply supply Ukraine as much as gas as it will have bought, and to the Russian border with Ukraine we will send as much gas as Europe should get and Ukraine should transit," Miller said in an interview on Rossiya-24 television.